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MagikDraggin
02-26-2007, 06:28 PM
Ok....someone please explain to me the proper operation of a heat riser...62 GT Hawk.

I was under the impression that when the motor is cold, the heat riser blocks exhaust gasses from going out the exhaust pipe and diverts them up to aiding in warming the choke/carburetor.

And I thought that once the motor is fully warmed up, the heat riser is supposed to open up and allow the exhaust gasses to flow unimpeded out the tailpipe.

On mine, the heat riser is blocking the exhaust all of the time....though it is working freely and is not bound up. Is that the way it's supposed to be?

Karl



http://img.photobucket.com/albums/v147/MagikDraggin/Other%20Stuff/62StudebakerGTHawk1-small.jpg
1962 GT Hawk 4sp

GTtim
02-26-2007, 06:49 PM
From your description it sounds okay to me. The spring is thermostatic so it will hold the valve open when the engine and the area under the hood is really hot. In my experience the valve almost always closes when the engine is idling except for the hottest days. The valve is mounted off center on the shaft so that when engine rpms increase the valve 'blows' open. You should be able to see this if you rev the engine a little while watching the valve.

Tim K.
'64 R2 GT Hawk

Rerun
02-26-2007, 06:56 PM
You are correct in your understanding of how the heat riser is supposed to work. The weight should open the valve, and the bimetallic spring should close it when cold. If it doesn't open when the engine warms up, it will cause the intake manifold to overheat, and can cause vapor lock. The additional back pressure on the exhaust isn't good either.

If it moves freely, but doesn't open when hot, I would be suspect of the bimetallic spring that closes the valve. Is it possible that someone wound the spring a half twist too tightly or installed the spring backwards?

Jim Bradley
'64 Daytona HT "Rerun"
http://home.earthlink.net/~bradley71771/images/Rerun.jpg

MagikDraggin
02-26-2007, 07:04 PM
quote:Originally posted by GTtim

From your description it sounds okay to me. The spring is thermostatic so it will hold the valve open when the engine and the area under the hood is really hot. In my experience the valve almost always closes when the engine is idling except for the hottest days. The valve is mounted off center on the shaft so that when engine rpms increase the valve 'blows' open. You should be able to see this if you rev the engine a little while watching the valve.

Tim K.
'64 R2 GT Hawk


Hmmm, no I didn't try it while revving the motor....I just "assumed", that would open on its own while idling hot. I'll hafta go out and take another look at it.

Thanks much

Karl

http://img.photobucket.com/albums/v147/MagikDraggin/Other%20Stuff/62StudebakerGTHawk1-small.jpg
1962 GT Hawk 4sp

GTtim
02-26-2007, 07:12 PM
It would be good to check the operation while revving the engine. The valve can be installed backwards and then the engine exhaust tends to hold it closed, which isn't a good thing.

Tim K.
'64 R2 GT Hawk

MagikDraggin
02-26-2007, 07:14 PM
quote:Originally posted by Rerun

You are correct in your understanding of how the heat riser is supposed to work. The weight should open the valve, and the bimetallic spring should close it when cold. If it doesn't open when the engine warms up, it will cause the intake manifold to overheat, and can cause vapor lock. The additional back pressure on the exhaust isn't good either.

Well, I'm glad to hear I wasn't going totally 'senile'. I am trying to figure out why I got such rotten fuel mileage while driving the Hawk back to Iowa from Ontario. On only one occasion I managed 17mpg and that was with a 35mph tailwind the entire time. All other fillups, the best I could get was between 12.5 and 13.5 mpg. I was told 20-23 is not out of the question...especially with the 4speed.

I checked the choke plate and that is opening up fine when warm...but that heat riser is always closed.....can be moved freely by hand, but always goes to the 'closed' position. As the previous poster mentioned, it should open up under higher rpms....I didn't try that yet.


quote:If it moves freely, but doesn't open when hot, I would be suspect of the bimetallic spring that closes the valve. Is it possible that someone wound the spring a half twist too tightly or installed the spring backwards?

Anything's possible I would suppose. It'd be nice to have a picture to see just how it's supposed to be put together. I have top bid on a shop manual on Ebay.....that should help me out a lot (I hope).

Thanks for the response,

Karl



http://img.photobucket.com/albums/v147/MagikDraggin/Other%20Stuff/62StudebakerGTHawk1-small.jpg
1962 GT Hawk 4sp

MagikDraggin
02-26-2007, 07:29 PM
quote:Originally posted by GTtim

It would be good to check the operation while revving the engine. The valve can be installed backwards and then the engine exhaust tends to hold it closed, which isn't a good thing.

Tim K.
'64 R2 GT Hawk


Ok, went outside and rapped it up a couple times. The butterfly valve does open up when I goose it, but it takes nearly 3000 rpm to get it to open...and once past the initial "surge", and while simply holding a steady rpm, it goes back closed again.

I take it, as the other poster suggested, that the spring is wound too tight. I'll mess with it some more tomorrow.

Karl

http://img.photobucket.com/albums/v147/MagikDraggin/Other%20Stuff/62StudebakerGTHawk1-small.jpg
1962 GT Hawk 4sp

GTtim
02-26-2007, 10:05 PM
Karl, I wouldn't worry too much about the heat riser valve. It sounds like it is operating within the normal range. You can disconnect the spring and let the valve go to full open and wire it in that position. It is really only necessary to have it operational in the coldest of conditions and then only for the brief time when the engine is running and really cold. I don't believe it will affect your mileage much. Other things like ignition timing, carburetor tune, rear axle ratio and driving habits will have much more effect.

Tim K.
'64 R2 GT Hawk

rockne10
02-26-2007, 10:25 PM
quote:I have top bid on a shop manual on Ebay
Karl,
With a $12 shipping charge be careful how high you bid. New reprints are available for $48 in hard copy or you can get the manual and both body and chassis catalogs on CD for $24.95.

MagikDraggin
02-26-2007, 11:08 PM
quote:Originally posted by GTtim

Karl, I wouldn't worry too much about the heat riser valve. It sounds like it is operating within the normal range. You can disconnect the spring and let the valve go to full open and wire it in that position. It is really only necessary to have it operational in the coldest of conditions and then only for the brief time when the engine is running and really cold. I don't believe it will affect your mileage much. Other things like ignition timing, carburetor tune, rear axle ratio and driving habits will have much more effect.

Tim K.
'64 R2 GT Hawk


I appreciate the comments. As far as I know, the Hawk has a 3.31 final gear. Driving in really cold wx as I was doing at 65-70 mph, I am sure, is not conducive to really 'great' mileage.

Under 'normal' circumstances, I wouldn't even consider doing that again. Summer driving, sure....but winter, with all the snow and ice and wind I had to deal with....the Hawk actually handled it all much better than this 'city slicker' did. :)

Karl

http://img.photobucket.com/albums/v147/MagikDraggin/Other%20Stuff/62StudebakerGTHawk1-small.jpg
1962 GT Hawk 4sp

MagikDraggin
02-26-2007, 11:16 PM
quote:Originally posted by rockne10


quote:I have top bid on a shop manual on Ebay
Karl,
With a $12 shipping charge be careful how high you bid. New reprints are available for $48 in hard copy or you can get the manual and both body and chassis catalogs on CD for $24.95.



Thanks for the heads up. I noticed the exhorbitant shipping charges (for "media" of all things...probably only cost a couple bucks at most to ship only 1 state away).

I'm not planning on bidding any higher than my opening bid. I saw at a Stude parts supplier where brand new manuals can be had for 48 clams. I wanna actual book and not a "CD".....that way I can drag the thing with me while poking around the vehicle.

I just think it's kinda cool having a car that I can actually work on and not have to have a doctorate in automotive diagnostics and computer programming. :D

Karl

http://img.photobucket.com/albums/v147/MagikDraggin/Other%20Stuff/62StudebakerGTHawk1-small.jpg
1962 GT Hawk 4sp

John Kirchhoff
02-27-2007, 10:52 AM
One wat to tell if the spring is working ok is to take one of those little propane torches and put heat to the spring. It'll start opening almost immediately afterwards and if it doesn't, you might want to chech further. If it doesn't open up all the way within say 30 seconds (it probably took half that time for the new one I was fiddling with) Jim might be correct in thinking someone wound the spring tighter than it is supposed to be. On the one I have, there's just a little stud sticking out that the end of the spring hook behind so it would be possible to wind it around again and hook it. Good thought Jim.

studelover
02-28-2007, 07:14 PM
I just started to clean my heat riser, It was stuck shut and had alot of carbon buiuld up, the looks new and the action after I soaked, cleaned and oiled it is night and day. The proper operation of this unit is very important to older cars, I learned this from my 1940 Plymouth, my plugs were fouling and it was hard to start until I put a kit in and rebuilt my heat riser now the car runs great, if you do not wind the spring too tight, when you turn the weight to open and let it go it should spring back into place. If you clean the opening so the flap can move freely it will not bind I ued a rat tail file.http://img.photobucket.com/albums/v145/mr1940/IMG_0135.jpg

Studebakers forever!

blackhawk
03-02-2007, 03:10 AM
quote:Originally posted by GTtim

Karl, I wouldn't worry too much about the heat riser valve. It sounds like it is operating within the normal range. You can disconnect the spring and let the valve go to full open and wire it in that position. It is really only necessary to have it operational in the coldest of conditions and then only for the brief time when the engine is running and really cold.Tim - actually you get carburetor icing at relatively warm temperatures (above zero) because the air will hold more moisture. I notice it in the fall before it really gets cold. I would never wire a heat riser in the open position or block the exhaust port through the intake manifold like some have suggested. If you don't get heat to the carb, the engine will stumble and balk. This is not a good thing when you accelerate into the traffic flow. I have also always used as thin a gasket as possible between the carb and intake manifold to facilitate transfer of heat to the carb. I live in a place where it gets cold in winter (Alaska), but much of the northern part of the lower 48 states also gets cold enough in winter to need that heat riser. Studebaker put one on the engine for a reason. Dale

MagikDraggin
03-02-2007, 11:41 AM
quote:Originally posted by studelover

I just started to clean my heat riser, It was stuck shut and had alot of carbon buiuld up, the looks new and the action after I soaked, cleaned and oiled it is night and day. The proper operation of this unit is very important to older cars, I learned this from my 1940 Plymouth, my plugs were fouling and it was hard to start until I put a kit in and rebuilt my heat riser now the car runs great, if you do not wind the spring too tight, when you turn the weight to open and let it go it should spring back into place. If you clean the opening so the flap can move freely it will not bind I ued a rat tail file. Studebakers forever!


Well, I believe I have gotten the heat-riser problem resolved. Apparently, the counterweight was 180 out of position (I hope that makes sense), in that while the spring was indeed holding the butterfly closed, the weight was on the wrong side of the "stop" and would only rotate a little bit...never able to really open.

It moved "freely" enough by hand, but in order to actually have it open, I had to rotate it in the "wrong" direction as opposed to how the exhaust gasses were trying to open it.

Repositioning the counterweight and "unwinding" one rotation of tension from the spring, the heat-riser now functions as I believe it was intended...ie, it is 'normally closed' and as the engine comes up to temperature, the spring relaxes its tension, thereby allowing the butterfly to come partially open at idle and fully open above 1200 rpms....and when the motor is shut off, the heat-riser returns to the closed position.

Also, the motor now "catches" immediately from a cold start and the fast idle cam holds the idle up around 1200 rpms until I "goose" the throttle and it drops down to approx 700 rpms, whereas before, I had to constantly fight with the thing to keep it running when cold.

I notice that overall throttle response is much better, and the tendancy of the motor to want to "load up" and try to stall under low speed/low rpm lugging (lack of power) is now gone as well.

I am anxious to get the Hawk back out on the highway again (if the weather around here would ever clear up) and see if the gas mileage has improved from the dismal 12-13 mpg I got while driving the car to Iowa after having purchased it.

I don't know for sure if I did it right, but at least it's working now. Once I receive the shop manual, I'll see how the factory recommends it be done.



http://img.photobucket.com/albums/v147/MagikDraggin/Other%20Stuff/62StudebakerGTHawk1-small.jpg
1962 GT Hawk 4sp

Dick Steinkamp
03-02-2007, 12:23 PM
quote:Originally posted by MagikDraggin
I am anxious to get the Hawk back out on the highway again (if the weather around here would ever clear up) and see if the gas mileage has improved from the dismal 12-13 mpg I got while driving the car to Iowa after having purchased it.


Karl,
You'll hear all kinds of claims about fuel mileage "back in the day". Truth is, while Studebakers generally were near the top of the heap as far as mileage was concerned, the heap wasn't very high :D.

My guess is that you will not see 20 MPG with your car (unless the speedometer/odometer is off, the ENTIRE tank is run at 40 MPH on level ground and/or down hill, or the tank isn't filled as much at the end of the trip as it was at the beginning). 17 (IMHO) would be a good average for 65 MPH cruise. Less than that is more probable due to hills, passing, some stopping, etc. 12-14 is a tad low, but within the range depending on speed, driving style, weather, terrain, etc.

Your car wasn't built as an "economy car". It was (is) a personal luxury car and/or a performance car. Mileage wasn't a big consideration to the buyers or to Studebaker (on that one). It is certainly desirable to have it in good tune and good repair for both mileage AND performance reasons, but it ain't no Honda Civic :D

http://thenobot.org/images/s2d/s2d_01.jpg

MagikDraggin
03-02-2007, 01:12 PM
quote:Originally posted by Dick Steinkamp
Karl,
You'll hear all kinds of claims about fuel mileage "back in the day". Truth is, while Studebakers generally were near the top of the heap as far as mileage was concerned, the heap wasn't very high :D.

My guess is that you will not see 20 MPG with your car (unless the speedometer/odometer is off, the ENTIRE tank is run at 40 MPH on level ground and/or down hill, or the tank isn't filled as much at the end of the trip as it was at the beginning). 17 (IMHO) would be a good average for 65 MPH cruise. Less than that is more probable due to hills, passing, some stopping, etc. 12-14 is a tad low, but within the range depending on speed, driving style, weather, terrain, etc.

Your car wasn't built as an "economy car". It was (is) a personal luxury car and/or a performance car. Mileage wasn't a big consideration to the buyers or to Studebaker (on that one). It is certainly desirable to have it in good tune and good repair for both mileage AND performance reasons, but it ain't no Honda Civic [:D


I appreciate your candor and honesty; I really do!

While I did not buy the Hawk with the notion of it being an "economy car", I was led on to believe that 20+ mpg on the highway was easily and routinely achievable, hence my disappointment when I only got 12-13 on my 1100 mile trip.

I guess it pays to do a little more research before making such a purchase, ehh? No big thing though...just a minor inconvenience having to stop for fuel every 200 miles or so. At least now I know and I can stop fretting over it.

As a matter of fact, after encountering ice and wind and snow and being held to driving 40 mph with a 35mph tailwind on Interstate 80, I did manage to rack up 17 mpg...the best of the entire trip.:)

Thanks again.

Karl

http://img.photobucket.com/albums/v147/MagikDraggin/Other%20Stuff/62StudebakerGTHawk1-small.jpg
1962 GT Hawk 4sp

John Kirchhoff
03-02-2007, 04:53 PM
Dick made some very valid points. Someone wanting good fuel mileage most likely bought a 6 cylinder Lark or at least had their Hawk equiped with overdrive. One thing I'd be curious about is the rear axle ratio of your car. I could be wrong, but I think a 3.31 was was pretty common in 4 speeds. At 60 mph, you're looking at over 2400 engine rpm which while great for accelleration, isn't exactly conducive to good fuel mileage on a large engine. In contrast, were the car equiped with a 3.54 and OD like my Hawk, the engine would be turning a little over 1800 rpm which is a pretty substantial decrease in rpm. If you could find a 3.03, that would drop the engine rpm by 200 @ 60 mph which would surely help mileage a bit.

Something else to consider is that with modern low profile tires, some of the mileage figured folks are quoting could be erroneous. With shorter tires the odometer is going to rack up more miles than actual. When compared to a 6.70X15 tire, a 205X70X15 is going to rack up about 7% more miles over what is true. In a 200 mile trip, that's an extra 14 miles which is going to be about one mile per gallon more than actual. Not all odometers are correct either, the one on my old '77 Dodge pickup read 10% more than actual and that was with factory installed tires. I've always been kind of a stickler about knowing the true fuel mileage of anything I've ever driven regardless of how many wheels it had. Auto fuel tanks or their guages are a notoriously inaccurate method of figuring mileage unless it's done over many, many tank fulls and by keeping track of the gallons shown on the pump. One other thing that was working against you was winter. For many years I made an 800 mile round trip to Chicago over New Years and my truck ALWAYS delivered one mpg less than when driven under comparable conditions in warm weather. Town driving also hurts compared to long distance interstate driving. My old Tempo would average 12.5% less mileage on a 20 mile round trip to work compared to interstate driving. Before you get all worked up into a lather over the mileage, I suggest you check the odometer for accuracy, keep a log of miles and gallons for several months as well as whether it's long haul or around town driving and see what you get. If it's still low, then it may be time to check for causes. There's no use throwing money at a problem that isn't there or comparing your accurate figures to someone elses inaccurate ones.

Dick Steinkamp
03-02-2007, 05:43 PM
quote:Originally posted by John Kirchhoff
Not all odometers are correct either, the one on my old '77 Dodge pickup read 10% more than actual and that was with factory installed tires.


I was just glancing through my October '62 issue of Road and Track today (for another reason). In this issue they test the new Avanti. On the car they test, indicated 60 MPH was actually 51.2 MPH [:0]. This is a NEW car most likely specially prepared for magazine tests. I wonder what the error was on production ones :(.



http://thenobot.org/images/s2d/s2d_01.jpg

MagikDraggin
03-02-2007, 06:23 PM
quote:Originally posted by John Kirchhoff One thing I'd be curious about is the rear axle ratio of your car. I could be wrong, but I think a 3.31 was was pretty common in 4 speeds. At 60 mph, you're looking at over 2400 engine rpm which while great for accelleration, isn't exactly conducive to good fuel mileage on a large engine.
Yes, you are correct, my '62 is indeed equipped with a 3.31 ratio rear gear. The tach was not consistent in its reading, but usually indicated 2650 rpm at 67 mph, indicated 70mph, (the speed I was traveling when weather permitted).


quote:Something else to consider is that with modern low profile tires, some of the mileage figured folks are quoting could be erroneous. With shorter tires the odometer is going to rack up more miles than actual. When compared to a 6.70X15 tire, a 205X70X15 is going to rack up about 7% more miles over what is true.

Understood and agreed. However, this Hawk is equipped with factory sized Coker radials. My own calculations indicate that the rear tires are slightly undersized, resulting in a 3mph error (higher) reading. This was also verified by doing an E/T calculation of how long it took to transverse one mile at an indicated 60mph.


quote:Auto fuel tanks or their guages are a notoriously inaccurate method of figuring mileage unless it's done over many, many tank fulls and by keeping track of the gallons shown on the pump.

By the time I had gotten to Iowa, I had made 10 fueling stops....I had amassed a pretty fair amount of information in which to arrive at my stated fuel consumption rate.

Oh and as far as the accuracy of the gauge is concerned....yes, I found out the hard way right off the bat, that that thing is not to be trusted, after running out of gas, even though it indicated there was still over an 1/8th of a tank remaining.


quote:One other thing that was working against you was winter.

Yep. I am quite aware of how warmer weather will affect the overall density of the fuel, resulting in higher mpg ratings.


quote:Before you get all worked up into a lather over the mileage, I suggest you check the odometer for accuracy,.....

Worked up into a lather? Now, that's funny!

Anyway, the bottom line here is that, for all intents and purposes, what sort of fuel mileage I could expect out of this Hawk was grossly misrepresented.

If that were indeed an accurate representation of the vehicles abilities, it would have been a welcomed surprise. It was not the primary reason or attribute which swayed me into purchasing the vehicle.

I bought it simply because I liked it. Now that I have driven it for a few hundred miles, even in some pretty adverse conditions, I like it even better.......even if it does "only" get 12-13 miles per gallon. This Hawk does it in style!:D

Thanks for your response,

Karl

http://img.photobucket.com/albums/v147/MagikDraggin/Other%20Stuff/62StudebakerGTHawk1-small.jpg
1962 GT Hawk 4sp

53k
03-05-2007, 08:49 PM
quote:Originally posted by Dick Steinkamp


quote:Originally posted by John Kirchhoff
Not all odometers are correct either, the one on my old '77 Dodge pickup read 10% more than actual and that was with factory installed tires.


I was just glancing through my October '62 issue of Road and Track today (for another reason). In this issue they test the new Avanti. On the car they test, indicated 60 MPH was actually 51.2 MPH [:0]. This is a NEW car most likely specially prepared for magazine tests. I wonder what the error was on production ones :(.

That sounds excessive. I remember most tests reporting the speedometers to be nearly 10% off. I wonder if they had the wrong pinion in that car. When I changed my '64 Avanti to a 3.07 and put 225x75x15 tires on it (almost the exact height of bias 6.70x15s) I also looked up the correct pinion and installed it. On the Route 66 trip I recorded 10.1 miles on a 10-mile test section on I-40 and my speedometer was reading right at 60 seconds for a mile at an indicated 60.


[img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/R-4.JPG[/img=right][img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/64L.JPG[/img=right][img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/64P.jpg[/img=right][img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/53K.jpg[/img=right]Paul Johnson
'53 Commander Starliner (since 1966)
'64 Daytona Wagonaire (original owner)
'64 Daytona Convertible (2006)
Museum R-4 engine

John Kirchhoff
03-05-2007, 09:50 PM
Before the mandated 85 mph speedos and requirements that they be accurate, nearly all motorcycles regardless of the brand and where they were built, were almost always 10% fast. the odometers might be accurate but they all led you to believe you were going faster than you actually were. I figure there were two reasons for that, to make the owner think his bike was faster than it really was and to get the rider to go slower. And it wasn't just the analog speedos, Kawasaki had digital speedos that were also 10% off. Now don't tell me that was an accident!